Shiftable light mask for camera lens

ABSTRACT

A structure basically resembling a lens cap and releasably frictionally engagable over the lens barrel of a particular design of camera. The end wall is, however, provided with a slightly less than one-quarter sector opening for registry with a one-quarter sector of the associated camera lens. The structure is designed for adjustable rotation relative to the associated lens barrel and the opening in the end wall thereof may therefore be successively registered with four one-quarter sectors of the associated lens so that the lens may be effectively masked in a manner enabling a single frame of film to have the four corner portions thereof successively exposed with the result that each film frame may be utilized to produce four different photographs.

nite States Patet H Simmons [54] SHIFTABLE LIGHT MASK FOR CAMERA LENS[76] Inventor: Roger R. Simmons, 2515 Yale,

Alamogordo, N. Mex. 88310 [22] Filed: April 19, 1971 [21] Appl. No.:135,097

UNlTED STATES PATENTS Splendore ..95/36 Linden ..95/36 PrimaryExaminer-John M. Horan Attorney-Clarence A. OBrien and Harvey B. Jacob-1 March 6, 1973 [57] ABSTRACT A structure basically resembling a lenscap and releasably frictionally engagable over the lens barrel of aparticular design of camera. The end wall is, however, provided with aslightly less than one-quarter sector opening for registry with aone-quarter sector of the associated camera lens. The structure isdesigned for adjustable rotation relative to the associated lens barreland the opening in the end wall thereof may therefore be successivelyregistered with four one-quarter sectors of the associated lens so thatthe lens may be effectively masked in a manner enabling a single frameof film to have the four corner portions thereof successively exposedwith the result that each film frame may be utilized to produce fourdifferent photographs.

4 Claims, 4 Drawing Figures PATENTED 6 I975 Roger R. Simmons 1N VENTORATTORNEY SHIFTABLE LIGHT MASK FOR CAMERA LENS The light mask of theinstant invention is constructed in generally the same manner as aconventional lens cover and includes a cylindrical body for frictionaltelescoping over a lens barrel and is provided with an end wall at oneend for closely overlying the outer surface of the associated cameralens. However, the end wall of theinstant invention is provided with aslightly smaller than one-quarter sector opening for registry with theassociated lens in four successive 90 relatively rotated positions. Inthis manner, each film frame of the camera may be exposed four times.

The light mask of the instant invention has been specifically designedfor use in conjunction with Polaroid cameras and also other cameras,with certain possible exceptions, when reasonably high speed film isused.

When at least reasonably high speed film is utilized in a Polaroidcamera the lens of the camera is adjusted so as to have a much smallerlens aperture and accordingly, the depth of field of the camera lens isincreased. Also, the lens structure of Polaroid cameras is such thatthey may be focused properly on an object closely spaced from thecamera. In this manner, even an object disposed immediately in front ofthe Polaroid camera lens is at least in partial focus at the film plane.Of course, if very slow speed film is used in a camera and the shuttermechanism is properly adjusted for slow speed film to increase the lensaperture, the depth of field of the camera would be reduced due to thelarger lens aperture and an object disposed immediately forwardly of thelens cannot be brought into even partial focus. Therefore, the lightmask of the instant invention can be best utilized on cameras only whenthe cameras have reasonably high speed film therein.

The main object of this invention is to provide a light mask for thelens of a Polaroid camera and positionable on the Polaroid camera lensin successive 90 rotated positions relative thereto so as to enable foursuccessive pictures to be taken with each film frame in the camera.

Another object of this invention, in accordance with the immediatelypreceding object, is to provide a light mask including portions thereofprojecting radially therefrom and viewable when looking through therange finder of a Polaroid camera to indicate to the user of the camerathat corner portion of the film frame and thus the range finder framewhich is not masked and therefore in which corner portion of the rangefinder frame the subject of the picture must be registered in order toproperly center the subject of the picture in that corner portion of thefilm frame to be exposed.

A final object of this invention to be specifically enumerated herein isto provide a shiftable light mask for a Polaroid camera lens inaccordance with the preceding objects and which will conform toconventional forms of manufacture, be of simple construction and easy touse so as to provide a device that will be economically feasible, longlasting and relatively trouble free in operation.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawingsforming a part hereof,

wherein like numerals refer to like parts throughout, and in which:

FIG. 1 is a front elevational view of a Polaroid camera with the lightmask of the instant invention operatively associated with the lens ofthe camera;

FIG. 2 is a perspective view of the light mask;

FIG. 3 is an enlarged fragmentary vertical sectional view takensubstantially upon the plane indicated by the section line 3-3 of FIG.1; and

FIG. 4 is a fragmentary perspective view of one of the radiallyoutwardly projecting peripheral portions of the light mask illustratingthe manner in which the positioning of the cut out sector opening in thefront wall of the light mask is indicated to the user of the camera inorder that the subject of the picture to be taken may be properlycentered in the proper sector of the range finder viewing frame.

Referring now more specifically to the drawings the numeral 10 generallydesignates a conventional form of Polaroid camera including a rangefinder 12 and lens barrel 14. In addition, the camera 10 includes ashutter release button 16 and a shutter cocking lever 18.

The light mask of the instant invention is referred to in general by thereference numeral 20 and comprises a generally cylindrical cap includinga cylindrical body 22 open at one end as at 24 and partially closed atthe other end by means of an end wall 26. The end wall 26 has a slightlyless than one-quarter sector opening 28 formed therein and the opening28 includes two right angled edges 30 and 32 intersecting at a point 34slightly laterally spaced from the center axis of the body 22 and anarcuate edge 36 extending between the ends of the edges 30 and 32 remotefrom the point 34 and having the center axis of the body 22 as itscenter of curvature. The point 34 is spaced laterally of the center axisof the body 22 along a radius thereof bisecting the arcuate edge 36 andaccordingly, light passing through the opening 28 and rearwardly throughthe lens barrel I4 is focused on the diagonally opposite quarter sectorof the film plane of the camera 10.

The light mask 20 further includes four generally square radiallyoutwardly projecting tabs 38 and each tab 38 includes a generally squareopening 40 therein with a square tab element 42 projecting inwardly fromthe corner portion of the opening 40 corresponding to the positioning ofthe opening 28 formed in the end wall 26 of the light mask 20.

In operation, the light mask 20 is frictionally telescoped over the lensbarrel 14 with one of the tabs 38 disposed uppermost and the sides ofthe uppermost tab 38 disposed vertically when the camera 10 is held in ahorizontal position such as that illustrated in FIG. I of the drawings.Then, as the user of the camera 10 views through the range or viewfinder 12, he can visually ascertain whether the upstanding sides of theuppermost tab 38 generally parallel the upstanding side edges of theviewing aperture of the range finder 12. If the tab side edges do notparallel the side edges of the viewing aperture through which the userof the. camera 10 is viewing the subject, the user of the camera 10 mayslightly rotate the lens mask 20 on the lens barrel 14 in order toachieve the correct positioning of the lens mask 20 on the lens barrel14. Then, the shutter cocking lever 18 may be depressed downwardly andthe subject to be photographed may be centered in that corner portion ofthe viewing aperture corresponding to the corner portion of the opening40 in which the tab element 42 is disposed. Thereafter, the shutterrelease button 16 may be depressed to take the first photograph.Thereafter, and without removing the film just exposed, the lens mask 20may be rotated 90 in either direction and the cocking lever 18 may againbe depressed. Then, the next subject to be photographed may be centeredin the corner portion of the viewing aperture corresponding to thepositioning of the tab element 42 of the next tab 38 positioned on topof the lens barrel 14 and the shutter release button 16 may be depressedto take the second picture. Thereafter, the lens mask 20 may besuccessively rotated 90 in the same direction so that the third andfourth pictures may be taken on a single sheet of film.

After all four pictures have been taken, the sheet film may be removedfrom the camera in a conventional manner and four additional photographsmay be taken on the next sheet of film.

In FIG. 4 of the drawings it may be seen that the positioning of eachtab element 42 may be utilized to determine in which corner portion ofthe range finder viewing aperture 44 the subject to be photographedshould be centered. Accordingly, and if the user of the camera willalways take the first picture with the tab element 42 registered withthe 12 through 3 oclock corner portion of the viewing aperture 44, theuser of the camera will always be able to determine how many quarterpictures have been taken and in which corner portion of the viewingaperture 44 the next subject to be photographed should be centered. Ofcourse, if the first photograph of each group of four photographs istaken with the tab element 42 disposed in the 12 through 3 oclockposition and the light mask 20 is always rotated in a clockwisedirection as viewed from the rear of the camera, little difficulty willbe encountered in assuring that the proper corner portions of each sheetof film will be successively exposed.

As hereinbefore set forth, the lens mask 20 has been found to operateeffectively when utilized in conjunction with reasonably high speedfilm.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly, all suitable modifications and equivalentsmay be resorted to, falling within the scope of the invention.

What is claimed as new is as follows:

1. In combination with a camera lens assembly of the type having aforwardly projecting lens barrel and operatively associated with acamera construction of the type enabling multiple exposures of a singleframe of film within the camera, a light shielding cap includingperipheral wall portions telescoped over the front of said lens barrelfor support of said cap therefrom, said cap including a transverseopaque front wall registered with and overlying the front end of saidlens barrel, said front wall having an opening formed therein in onecorner sector thereof defined by the intersection of right angleddiameters of the center axis of said lens barrel, said opening includingedge portions thereof extending generally along said diameters, said capincluding four clrcum erentrally spaced and radially outwardlyprojecting tabs thereon, said tabs each including at least one straightedge portion thereof that parallels one of said generally straight edgeportions of said opening, said cap including four circumferentiallyspaced and radially outwardly projecting tabs thereon, said tabs eachincluding a rectangular opening therein with visually ascertainablemeans indicating corner portions of said rectangular openingscorresponding to the sector positioning of said front wall opening, thesides of said rectangular openings generally paralleling said diameters.

2. The combination of claim 1 wherein said visually ascertainable meanscomprise generally rectangular tab elements supported within saidcorresponding corner portions.

3. The combination of claim 2 wherein said camera includes a view finderwindow through which the operator of the camera may view the areaaligned with the center axis of said lens barrel, one of said tabs beingviewable through said window.

4. A cap for disposition over the front end of a camera lens barrel,said cap including an opaque front wall for registry with and overlyingthe front end of said barrel, said front wall having an opening formedtherein in one corner sector thereof defined by the intersection ofright angled diameters of said cap, said opening including generallystraight edge portions thereof generally paralleling and at leastslightly spaced from said diameters, said cap including fourcircumferentially spaced and radially outwardly projecting tabs thereon,said tabs each including a rectangular opening therein with visuallyascertainable means indicating corner portions of said rectangularopenings corresponding to the sector positioning of said front wallopening, the sides of said rectangular openings paralleling saiddiameters.

1. In combination with a camera lens assembly of the type having aforwardly projecting lens barrel and operatively associated with acamera construction of the type enabling multiple exposures of a singleframe of film within the camera, a light shielding cap includingperipheral wall portions telescoped over the front of said lens barrelfor support of said cap therefrom, said cap including a transverseopaque front wall registered with and overlying the front end of saidlens barrel, said front wall having an opening formed therein in onecorner sector thereof defined by the intersection of right angleddiameters of the center axis of said lens barrel, said opening includingedge portions thereof extending generally along said diameters, said capincluding four circumferentially spaced and radially outwardlyprojecting tabs thereon, said tabs each including at least one straightedge portion thereof that parallels one of said generally straight edgeportions of said opening, said cap including four circumferentiallyspaced and radially outwardly projecting tabs thereon, said tabs eachincluding a rectangular opening therein with visually ascertainablemeans indicating corner portions of said rectangular openingscorresponding to the sector positioning of said front wall opening, thesides of said rectangular openings generally paralleling saiddiameters.
 1. In combination with a camera lens assembly of the typehaving a forwardly projecting lens barrel and operatively associatedwith a camera construction of the type enabling multiple exposures of asingle frame of film within the camera, a light shielding cap includingperipheral wall portions telescoped over the front of said lens barrelfor support of said cap therefrom, said cap including a transverseopaque front wall registered with and overlying the front end of saidlens barrel, said front wall having an opening formed therein in onecorner sector thereof defined by the intersection of right angleddiameters of the center axis of said lens barrel, said opening includingedge portions thereof extending generally along said diameters, said capincluding four circumferentially spaced and radially outwardlyprojecting tabs thereon, said tabs each including at least one straightedge portion thereof that parallels one of said generally straight edgeportions of said opening, said cap including four circumferentiallyspaced and radially outwardly projecting tabs thereon, said tabs eachincluding a rectangular opening therein with visually ascertainablemeans indicating corner portions of said rectangular openingscorresponding to the sector positioning of said front wall opening, thesides of said rectangular openings generally paralleling said diameters.2. The combination of claim 1 whereiN said visually ascertainable meanscomprise generally rectangular tab elements supported within saidcorresponding corner portions.
 3. The combination of claim 2 whereinsaid camera includes a view finder window through which the operator ofthe camera may view the area aligned with the center axis of said lensbarrel, one of said tabs being viewable through said window.